Look Out Below!

Efrain, our 24-year-old English-speaking guide, rode in front, and the company's safety rules prohibited us from passing him. Behind the pack was Franz, another guide, who would not pass us. At the end came our microbus, now transformed into a support vehicle for mechanical and medical difficulties.

For almost 20 miles at its start, the world's most dangerous road is paved and not too terribly dangerous. What it is, however, is fast. In seconds, the wind was flapping my clothes and numbing my face as I flew into the upper reaches of the Unduavi River canyon. My nose ran, my eyes watered and my ears hurt, but I couldn't stop grinning. I was moving faster than I ever had in anything without an engine, catching -- then passing -- several buses and heavy trucks. If you've never ridden a bike past a truck topped with blanket-covered Bolivians, I can only say that it is an odd, exhilarating sensation.

As we descended, the air turned warmer, the vegetation became greener and the clouds were no longer so far below us. Several times, Efrain stopped so we could take pictures.

After about 2½ hours, the pavement suddenly ended as we came upon a T-shaped intersection. Dead ahead, the ground dropped sharply, leaving only whirling clouds riding the warm updrafts from the tropical valley below. To the right lay our path, a bumpy thread of rocks and mud leading into the jungle.

Efrain stepped off his bike. This, he said, was the dangerous section.

"Dangerous?" asked a young Dutch woman in our group.

"But for us it is okay," Efrain said.

There was one essential rule for this section of the road, he told us gravely: Downhill traffic, ourselves included, stayed to the left, next to the cliff. Ascending trucks would be on the inside, and these were best avoided.

This arrangement is designed to give descending vehicles a better view of the cliff's edge -- and, hence, improved odds of not going over it -- when they back up to allow another vehicle to pass.

After his brief safety talk and a moment's rest, Efrain started downhill again, and the group strung out behind him, our bikes rattling across the rocks and uneven ground. The road's steep grade and my fear of flying over the cliff kept my right hand locked in a death grip on the back brake, and I tried hard to find the perfect balance of speed and control, adrenaline and caution.

An undulating blanket of green spread out below me, and small waterfalls occasionally splattered my legs as they fell onto the road. At times, however, my attention was necessarily diverted from the view by Efrain, who waved us to the side whenever he saw a truck or bus approaching.

On one such stop, he pointed to a bus rounding a particularly sharp curve. A truck had gone over that edge about three weeks earlier, he told me. I asked if there were muertos, the Spanish word for deaths.